If your brand has a website, more people are likely to come to it from search engines than anyplace else according to Forrester. That means Search Engine Optimization (SEO), a methodology of strategies, techniques and tactics used to secure a high-ranking placement in the search results pages, is as essential means of marketing for anybody doing business on the internet.

Is SEO a science or an art? Science is facts or truths systematically arranged showing the operation of general laws. Art is the conscious use of skill and creative imagination.

Here are 11 reasons SEO is a science; 14 reasons it’s an art.

SEO is a science because it operates according to mathematical laws that are statistical reliable and predictive of human behavior.

Demand for those keywords, if it is increasing or decreasing over time, is measurable through Google Trends. So you can even predict what their value is both now and in the future.

Search rank of your domain or your competitors’ can be tracked for any keyword or key phrase to help understand the rise or fall in rank by Ispionage or Rank Checker.

Number of links that increase or decrease your authority in a particular area and also influences search rank can be found through Majestic SEO or Alexa.

Value the links, whether they are high or low value authority, can be determined by SEO Majestic and Marketing Grader.

Machines, or search bots, that do the searches on Google, Yahoo, Bing and other search engines are programmed to even identify the underlying meanings behind by keywords to returns the most meaningful results. The is called Semantic Search, predicted to play a more important role with the Google “Hummingbird” algorithm.

Rob Petersen is an experienced advertising and marketing executive and President of BarnRaisers, a full service digital marketing agency that builds brands based on proven relationship principles and ROI. He is on the MBA Faculty of Rutgers CMD and is the author of two books on digital marketing.